Zip sealed flexible pouch

ABSTRACT

front wall, and further comprising a closure mechanism comprising a thin membrane patch bonded to said pouch about a periphery of said opening, a platform bonded to said thin membrane patch, said platform including a window formed therein and a plurality of cutting surfaces adjacent said window, and a pull strip bonded to said thin membrane patch and attached to said platform by a frangible membrane, wherein a removal of the pull strip ruptures said frangible membrane and tears said thin membrane patch at said cutting surfaces.

BACKGROUND

The present invention relates generally to flexible containers forliquids and gels, and dry contents, and more particularly to adisposable flexible pouch with a removable strip that can be pulled togain access to the contents of the pouch.

Flexible beverage containers are well known in the art, with many shapesand sizes. Common configurations include pouches with straw holes thatcan be punctured to permit access to the beverage contained therein.Other types of packages include those with spouts, including threadedspouts that employ a twist-off cap. U.S. patent application Ser. No.11/471,930 filed Jun. 21, 2006 by the present inventor and assigned tothe present assignee discloses a method for attaching a spout to aflexible container, and the contents of that application areincorporated fully herein by reference. Another method is a “cut andpour” type of emptying the contents of a stand-up pouch (a pouch withthe gusset on the bottom of the pouch).

While twist-off spouts can be utilized effectively in certainconditions, detachable caps can be misplaced or lost. If a mode ofaccess can be improved to make it easier to open the container, thisimproved mode will enjoy success in the market place. However, there aremany difficulties that arise when working with thin films that form thebody of flexible beverage pouches, and it is important to be cognizantof waste and spillage that can arise by poorly constructed openingmechanisms that cause premature puncture or are too difficult to open.There is a need in the art for a pouch with an opening mechanism that isboth secure, sterile, and easy to implement in conjunction with thinfilm pouches. Many stand-up pouches (gusset on the bottom) use a simplemethod of opening with just a cut and pour feature, although the resultsof using this method can be messy and not re-closable. However, with aside gusseted pouch, one cannot easily cut the top of this pouch andpour, as cutting the top will jeopardize the structure of the pouch andmay cause the contents to spill. The present invention provides a lowcost solution for both pouch types, including other pouch shapes aswell.

SUMMARY OF THE INVENTION

The present invention is characterized by a thin film pouch with a frontwall, and rear wall, and an opening in said front wall, and furthercomprising a closure mechanism comprising a thin membrane patch bondedto said pouch about a periphery of said opening, a platform bonded tosaid thin membrane patch, said platform including a window formedtherein and a plurality of cutting surfaces adjacent said window, and apull strip bonded to said thin membrane patch and attached to saidplatform by a frangible membrane, wherein a removal of the pull stripruptures said frangible membrane and tears said thin membrane patch atsaid cutting surfaces.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a is an elevated perspective view of a first preferred embodimentof the present invention prior to release of the pull tab;

FIG. 1 b is an elevated perspective view of a first preferred embodimentof the present invention with the pull tab partially released;

FIG. 1 c is an elevated perspective view of a first preferred embodimentof the present invention with the pull tab fully released;

FIG. 2 is an elevated perspective view of the embodiment of FIG. 1 afterrelease of the pull tab;

FIG. 3 is an enlarged, lower perspective view of the pull strip andplatform of the present invention;

FIG. 4 is an enlarged, elevated perspective view of the pull strip beinglifted off the platform;

FIG. 5 a is an enlarged, cross-sectional view of the pull strip andplatform prior to actuation of the pull tab;

FIG. 5 b is an enlarged, cross-sectional view of the pull strip andplatform after actuation of the pull tab;

FIG. 6 a is an enlarged, cross-sectional view of a second embodiment ofthe pull strip and platform prior to actuation of the pull tab;

FIG. 6 b is an enlarged, cross-sectional view of the embodiment of FIG.6 a after actuation of the pull tab;

FIG. 7 a is an enlarged, cross-sectional view of a re-closableembodiment of FIG. 5 prior to actuation of the pull tab; and

FIG. 7 b is an enlarged, cross-sectional view of the embodiment of FIG.7 a after actuation of the pull tab.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1 a-1 c illustrate a flexible pouch having a pull strip as part ofa zip release opening that can be actuated to tear an elongate strip ofpouch away from the body of the pouch to gain access to the contentstherein. The pouch 10 includes a body having a base 12, a front surface14, a rear surface 16, side surfaces 18, and a top 20. The pouch mayhave a gable design as shown, or can take the form of a brick,triangular, or pillow-shaped pouch. The pouch 10 may be created by anyof the many known techniques for formulating a closed container thatincorporates a thin walled member. As further shown in FIG. 1, the pouch10 of the present invention includes a pull strip 22 including a freeend 22 a that can be grasped between a thumb and forefinger to actuatethe zip release opening 25. The free end 22 a of the pull strip 22preferably includes a grasping member can take many forms, such as aspherical anchor 24, annular ring, or flat tab with ridges that can beeasily grasped. The pull strip 22 is pulled back to engage the thin wall32 of the pouch's outer skin, and then retracted to tear open anelongate aperture 25 on the pouch 10 to expose the pouch's interior.When the pull strip 22 is fully retracted as shown in FIG. 1 c, thecontents 28 of the pouch 10 can be poured out or otherwise accessed inan expeditious manner as shown in FIG. 2. Note that the pouch 10 can beformed with a pouring ledge 30 or other spout structure to prevent fluidfrom dribbling down the front surface 14 of the pouch during pouring.The coupling of the pull strip 22 to the pouch will now be described inmore detail.

FIGS. 3 and 4 illustrate the operation of the pull strip 22 from initialdeployment to full release. As shown in FIG. 4, the pull strip 22comprises an elongate plastic strip 36 that is affixed to a rectangularplatform 38 with an elongate window 44 disposed therein and covered bythe plastic strip 36. On the border 39 of the platform 38 that definesthe window 44 are first and second rows of downwardly directed cuttingteeth 42 along each longitudinal edge, and a larger cutting tooth 46 atan edge where the free end 22 a is located. In FIG. 3 a, the platform 38is bonded to a thin membrane patch 41 that connects the platform 38 tothe edge 32 of the pouch. The plastic strip 36 is also bonded to thethin membrane patch 41 a, where the bonding of the plastic strip 36 tothe membrane patch 41 a is surrounded by the cutting teeth 42, 46. Inbetween the bonding of the patch 41 aand the patch 41 at the perimeterof the platform 38 is a slightly raised surface 37 (FIG. 3 a). Thecutting teeth 42, 46 are fully concealed beneath the raised surface 37of the membrane patch 41 prior to actuation of the pull strip 22. As thepull strip 22 is initially lifted as shown in FIG. 3 b, the plasticstrip 36 begins to separate from the platform 38, and the thin filmmembrane 41 a attached to the plastic strip 36 is pulled upward againstthe cutting teeth 42. The cutting teeth 42 pierce the thin membrane 41,beginning with the tooth 46, as shown in FIG. 3 b. As the plastic strip36 is further pulled away from the platform 38 as shown in FIG. 3 c, theportion of the membrane 41 a that is bonded to the lower surface of theplastic strip 36 is retained by the plastic strip 36 as the cuttingteeth 42 sever the surrounding membrane, creating an aperture 25 in thepouch through the window 44 of the platform 38. FIG. 3 d shows the pouchopening with the plastic strip 36 separated from the platform 38 tofully expose the window 44 and create the pour spout for the pouch.

FIG. 5 a shows a cross-sectional view of the closure prior to actuationof the pull strip 22. The plastic strip 36 carries the pull tab 24 at aproximal end, and rests between edges 39 of the platform 38. Cuttingteeth 42 are disposed along the edges 39 and project below the lowersurface of the platform 38. The patch 41, 41 a are bonded to the bottomsurface of the plastic strip 36 and the bottom surface of the platformon opposite sides of the cutting teeth 42. To enhance ultrasonic bondingof the platform 38 and the plastic strip 36 to the membrane 41, smallraised tabs can preferably extend from those surfaces where said bondingoccurs. The plastic strip 36 is attached to the cutting teeth 42, 46 bya thin frangible sheet 47 in a septic embodiment shown in FIG. 5. Thethin sheet 47 is severed when the pull tab 22 is actuated, separatingthe plastic strip 36 from the cutting teeth 42 as shown in FIG. 5 b.This embodiment is aseptic because the plastic strip never contacts thecontends of the pouch, but rather the pouch is preserved in an asepticcondition until it is opened. In FIG. 6 a, an alternative embodiment isillustrated (non-septic) where the thin membrane 41 a is omitted. Here,the platform 38 is bonded to the membrane patch 41, which in turn isbonded to the outer edge of the pouch 10. The pull strip 22 is connectedto the platform 38 by a thin sheet 47, but the bottom surface 51 of theplastic strip 36 is exposed to the interior of the pouch 10. As shown inFIG. 6 b, when the pull strip 22 is actuated, the sheet 47 is severedand the window 44 of the platform 38 is thereby exposed. In thisembodiment, the cutting teeth 42, 46 can be minimized or omitted. FIGS.7 a and 7 b illustrate another embodiment of the closure that can bere-closed after opening. The platform 38 is formed with retaining ledges55 a,b that extend slightly over the outer edges of the plastic strip36. After the pull tab 22 is actuated and the sheets 47 are ruptured,the contents of the pouch can be accessed. If it is desired to re-closethe opening, the plastic strip 36 can be returned to the platform 38 andthe retaining ledges 55 a,b flex to allow the plastic strip to return tothe platform 38 where it is held in place by the retaining ledges.Although the aseptic condition has been eradicated by the opening of theplastic strip 36, for short term usages a simple resealing of the pouchis all that is needed. A non-septic version (see FIG. 6) can also bemade with a re-closable closure as just described.

The closure of the present invention can be made of any sturdy plasticsuch as polyethylene or polypropylene, as long as economic bondingtechniques such as, for example, ultrasonic bonding, will work with theplastic. Because the closure is molded in the closed position, it can bemade from a single cavity mold, which is atypical for this type ofclosure. Using a single cavity mold significantly reduces the costs ofmanufacturing the closure, making the present invention very economicalcompared with alterative closure means.

The foregoing descriptions are intended to be illustrative of variousembodiments within the scope of the present invention, and are notintended to be limiting or exclusive. One of ordinary skill in the artwould readily appreciate many alternatives and deviations from thoseembodiments described above, and the invention is intended to includeall such alternatives and deviations. Accordingly, the scope of theinvention should be construed according to the ordinary meaning of theterms set forth in the appended claims in view of the foregoingdescriptions.

1. A closure mechanism for a thin walled pouch comprising: a thinmembrane patch secured to said thin walled pouch; a platform bonded tosaid thin membrane patch, said platform formed with a window and aplurality of downwardly directed cutting surfaces; and an elongateremovable strip overlaying said window and connected to said platform bya frangible member, said frangible member ruptured by removal of saidelongate strip.
 2. The closure mechanism of claim 1 wherein saidelongate removable strip is bonded to said thin membrane patch, andremoval of said elongate strip tears said thin membrane patch along saidcutting surfaces.
 3. The closure mechanism of claim 2 wherein saidelongate removable strip has a pull tab.
 4. The closure mechanism ofclaim 2 wherein said cutting surface comprise a plurality of downwardlydirecting teeth.
 5. The closure mechanism of claim 2 wherein saidplatform includes first and second retaining ledges to retain saidelongate removable strip against said platform after said frangiblemember is ruptured.
 6. The closure mechanism of claim 1 where saidplatform is ultrasonically bonded to said thin membrane patch.
 7. Theclosure mechanism of claim 1 wherein said closure mechanism is made ofpolyethylene.
 8. The closure mechanism of claim 1 wherein said closuremechanism is made from a single cavity mold process.
 9. A thin walleddisposable pouch having a front wall, and rear wall, and an opening insaid front wall, and further comprising a closure mechanism comprising:a thin membrane patch bonded to said pouch about a periphery of saidopening; a platform bonded to said thin membrane patch, said platformincluding a window formed therein and a plurality of cutting surfacesadjacent said window; a pull strip bonded to said thin membrane patchand attached to said platform by a frangible membrane; wherein a removalof the pull strip ruptures said frangible membrane and tears said thinmembrane patch at said cutting surfaces.
 10. The pouch of claim 9wherein said elongate removable strip has a pull tab.
 11. The pouch ofclaim 9 wherein said cutting surface comprise a plurality of downwardlydirecting teeth.
 12. The pouch of claim 9 wherein said platform includesfirst and second retaining ledges to retain said elongate removablestrip against said platform after said frangible member is ruptured. 13.The pouch of claim 9 where said platform is ultrasonically bonded tosaid thin membrane patch.
 14. The pouch of claim 9 wherein said closuremechanism is made of polyethylene.
 15. The pouch of claim 1 wherein saidclosure mechanism is made from a single cavity mold process.